I don't currently hav a OS on that drive, i have XP on my internal 40g but the reason I'm not putting it on that (as i have already several times) is because that has a 10g partition on it with my xp back up so I'm only left with about 28g now every time i put Vista on that i only have 14g to play with minus all the progams to reinstall so I'm down to about 10g.
what happens when when install Vista even clean install is it stores your old folder in a untouchable folder so for e.g. the 6g of programs i have on now take me down to 20g then when vista installs it takes another 6g off me to store those xp files which i cant touch or delete, so now I'm left with 14g but still have to reinstall all my software(hope you are still with me)
After that I'm down to about 10g that is not acceptable to me, the only other way is to delete all my software down to just the OS and then install it.